/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id: strtoofft.c,v 1.13 2007-11-05 09:45:09 bagder Exp $
 ***************************************************************************/

#include "setup.h"
#include "strtoofft.h"

/*
 * NOTE:
 *
 * In the ISO C standard (IEEE Std 1003.1), there is a strtoimax() function we
 * could use in case strtoll() doesn't exist...  See
 * http://www.opengroup.org/onlinepubs/009695399/functions/strtoimax.html
 */

#ifdef NEED_CURL_STRTOLL

/* Range tests can be used for alphanum decoding if characters are consecutive,
   like in ASCII. Else an array is scanned. Determine this condition now. */

#if('9' - '0') != 9 || ('Z' - 'A') != 25 || ('z' - 'a') != 25
#include <string.h>

#define NO_RANGE_TEST

static const char valchars[] =
	"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
#endif

static int get_char(char c, int base);

/**
 * Emulated version of the strtoll function.  This extracts a long long
 * value from the given input string and returns it.
 */
curl_off_t
curlx_strtoll(const char *nptr, char **endptr, int base)
{
	char *end;
	int is_negative = 0;
	int overflow;
	int i;
	curl_off_t value = 0;
	curl_off_t newval;

	/* Skip leading whitespace. */
	end = (char *)nptr;
	while (ISSPACE(end[0]))
	{
		end++;
	}

	/* Handle the sign, if any. */
	if (end[0] == '-')
	{
		is_negative = 1;
		end++;
	}
	else if (end[0] == '+')
	{
		end++;
	}
	else if (end[0] == '\0')
	{
		/* We had nothing but perhaps some whitespace -- there was no number. */
		if (endptr)
		{
			*endptr = end;
		}
		return 0;
	}

	/* Handle special beginnings, if present and allowed. */
	if (end[0] == '0' && end[1] == 'x')
	{
		if (base == 16 || base == 0)
		{
			end += 2;
			base = 16;
		}
	}
	else if (end[0] == '0')
	{
		if (base == 8 || base == 0)
		{
			end++;
			base = 8;
		}
	}

	/* Matching strtol, if the base is 0 and it doesn't look like
	 * the number is octal or hex, we assume it's base 10.
	 */
	if (base == 0)
	{
		base = 10;
	}

	/* Loop handling digits. */
	value = 0;
	overflow = 0;
	for (i = get_char(end[0], base);
			i != -1;
			end++, i = get_char(end[0], base))
	{
		newval = base * value + i;
		if (newval < value)
		{
			/* We've overflowed. */
			overflow = 1;
			break;
		}
		else
			value = newval;
	}

	if (!overflow)
	{
		if (is_negative)
		{
			/* Fix the sign. */
			value *= -1;
		}
	}
	else
	{
		if (is_negative)
			value = CURL_LLONG_MIN;
		else
			value = CURL_LLONG_MAX;

		SET_ERRNO(ERANGE);
	}

	if (endptr)
		*endptr = end;

	return value;
}

/**
 * Returns the value of c in the given base, or -1 if c cannot
 * be interpreted properly in that base (i.e., is out of range,
 * is a null, etc.).
 *
 * @param c     the character to interpret according to base
 * @param base  the base in which to interpret c
 *
 * @return  the value of c in base, or -1 if c isn't in range
 */
static int get_char(char c, int base)
{
#ifndef NO_RANGE_TEST
	int value = -1;
	if (c <= '9' && c >= '0')
	{
		value = c - '0';
	}
	else if (c <= 'Z' && c >= 'A')
	{
		value = c - 'A' + 10;
	}
	else if (c <= 'z' && c >= 'a')
	{
		value = c - 'a' + 10;
	}
#else
	const char * cp;
	int value;

	cp = memchr(valchars, c, 10 + 26 + 26);

	if (!cp)
		return -1;

	value = cp - valchars;

	if (value >= 10 + 26)
		value -= 26;                /* Lowercase. */
#endif

	if (value >= base)
	{
		value = -1;
	}

	return value;
}
#endif  /* Only present if we need strtoll, but don't have it. */
